Even the most compelling legal argument won’t work if you play dirty during a trial. That’s the lesson from the latest chapter in the long-running legal battle between pharma giants Gilead Sciences and Merck. Back in June, a federal judge found that Gilead didn’t have to pay up to $200 million in damages for infringing on some of Merck’s patents due to misconduct by Merck including lying under oath.

Judge Beth Labson Freeman called out Merck for “systematic and outrageous deception in conjunction with unethical business practices and litigation misconduct,” which including lying under oath at deposition and trial.

Now, Freeman just ruled in Gilead’s favor yet again, deciding that Merck needs to pay its competitor’s attorney fees in the case. The lawsuit related to sofosbuvir, the active ingredient in Gilead’s blockbuster hepatitis C drugs, which have been extremely successful at curing patients with the liver disease. MB